Recoil buffer for cutter bars



Jan. 31, 1933. N, STONE RECOILBUFFER FOR CUTTER BARS Filed 001:. 24, 1931 2 Sheets-Sheet 1 Jan. 31, 1933. N. B. STONE 1,895,840

RECOIL BUFFER FOR CUTTER BARS Filed Oct. 24, 1931 2 Sheets-Sheet 2 Patented Jan. 31, 1933 LJNITED STATEs NATHANIELMB. s'ronnioniwnsrrmoron, DISTRICT onoon MBIA nncorr. nurrnn iron CUTTER BARS Application med October 24, 1931. Serial No. 570,913.

This invention relates to agricultural machines wherein reciprocating cutter bars form a part thereof, the primary object of the invention being to improve generally the con 5 struction as described in my Patent No. 1,844,188, February 9, 1932.

' An important object of'the invention is to provide a buffer for reciprocating cutter bars wherein compression springs are used to absorb the severe shocks directed to the pitman' and cutter bar mechanism when the cutter bar nears the end of its stroke. A further object of the invention is the provision of yieldable-means for overcoming the inertia of the blade and at the same time supply suflicient power to impart the initial movement to the cutter bar'tostart the cut ter bar on its return stroke." I A still further object ofthe invention is to provide a device of this character wherein. the springs of the mechanism; are mounted to provide a small andcompact structure, the springs being of the compression type andso arranged that the pressure thereof will be suflicient to require only slight movementofthe springs and levers of the buffer to accom-' plish the purpose of the invention, thereby reducing wear on the springs and levers of the device to a minimum. 1

Another important object of the invention is the provision of a device of this character including levers having bearings of a construction to permit .the levers to rock freely within the frame of the device by reducing friction between the bearings and levers.

With the foregoing and other objects in view which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed it being understood that changes in the precise embodiment of the invention herein disclosed, may bemade within the scope of what is claimed, without departing from the spirit ofthe invention;

Referring to the drawings: 1 a 7 Figure 1 is a fragmental plan viewof the cutterbar of an agricultural machine showing the device constructed in accordance with" V the essence of the invention. 1 I i the inventionas applied thereto, the cover of the device having been removed. Figure 2 is a vertical sectional view through the cutter bar head and the buffer forming Figure 3 is a sectional view through the device, parts thereof being shown in elevation.

Figure 4 is a sectional view through one end of the frame, showing one of the levers in elevation. i l 1 Figure 5 is a transverse sectional view; throughthebuifer support. I

Figure 6 is a fragmental elevation'al-view of one of the levers, showing the manner of mounting the levers on the frame bearings;

Figure 7 is a'perspective view of one of the bearings. Figure 8 is a planview of the invention. 7

Figure 9 isa vertical sectional view through the frame, the springs and levers being shown in elevation; I Figure 10 is a vertical sectional view through the central portion of the device.

Figure 11 is asectional view taken on line 11-11 of FigurelO. Referring to the-drawings in detail, the device as'illustrated includes the usual cutter bar of an agricultural machinethat comprises a finger bar 5 and sickle bar 6, the fingerv bar being formed with a channel way in which the sickle bar 6 moves.

Rising from the rear edge of the finger bar, is a flange8, which is formed with inclined side'edges, the flange actingas a support for the buffer, to be hereinafter more" fully described... I

The buffer comprises a rectangular frameindicated generaliy by the reference character 9, which frame is provided witha depending fiangolO having inturned side edges p-rovid ing flanges overlying .the flange 8, .to removably mount the buffer. A I A notch is formed in one edgeof. the flange 8, and accommodates oneend of the setscrew 11 thatis carried by the flange 10 to lock the buffer in position. i =5 Rising from the frame isa striking lug. 12 which may be struck by a suitable tool fto drive the frame to its proper position, i

of a modified fOI 'IIIl frame 9, to the end that by adding or remov-- ing shims, the throw of the levers may be adjusted.

Extending longitudinally of the ends of the frame 9, and disposed in the inner surfaces thereof are grooves 14 providing seats for the fulcrum bars 15 that are shown as provided with flat rear surfaces, and half roundor contacting surfaces.

Teeth 16 extend from the fulcrum bars,

and fit within notches 17 of the levers 18'. These-levers, 18 are formed preferably of sheet steel material, and are provided with wide.

upper portions 19 that taper off to substantiallynarrowportions 20, the portions 29 eX- tending appreciable distances below the portions 19, where they will be engaged by'the Cutter. bar head 21 as it reciprocates cutter bar. I

The buffer also includes an outer expansion spring 22, and inner expansion springs 23 and 24 respectively, the springs being nested or interposed in such a way that the forces thereof will be proportionate. The term expansion spring is used to describe a'spring which is normally compressed. I

, Caps 25 fit over the ends of the springs, and as shown are provided with transversely disposed'notches that provide seats for the bearing bars 26, which bearing bars are :also PlQV-ided with flat inner surfaces and half round outer surfaces, the lugs at the ends thereof being fittedin notches in the levers- Due t this construction, it will be seen with the that the half round surfaces of the fulcrum bars and bearing barsengage the flat inner and outer surfaces of the levers 18 permitting the levers to rock overthe half round surfaces of the fulcrum bars and-bearings to bars, bearings and levers will be reduced to:

and eliminate anypossibility of the bearingsor levers shifting laterally.

The levers 18 are formed with outwardly curved upper extremities 27 so constructed that a suitable tool may be positioned over the'outwardly curved ends. of the levers and the springs may be compressed to permit the removalof the buffer proper, from itsframe.

Hooksare formed at the lower ends of the lovers, and are designed to engage :a tool suchas shown in dotted lines in Figure?) for holding the-lower ends of the levers against outward movement, when the spring is ten-.

sinned to :permit the removal thereof.

wInorder that the levers1'8 may be made of exceptionally light material, and. at the same time be sufliciently strong to withstand the action of the cutter head, reinforcing ribs 28 are provided, the ribs extending to points near the lower ends of the levers, as shown by Figure 4 of the drawings.

It might be further stated that the construction of the depending flange 10 is such that an opening is provided between the flanges 8 and 10, to permit a bar to be positioned therein so that a prying action of the b'ar wil laot to move the buffer upwardly and permi of it ready removal- Due to the construction of the springs, a

great pressure is exerted on the cutter head after each power stroke of the cutter head, to the end that the momentum; of the cutter ba e- 1d cutter-h d s st red, an the-pow r thus directed to-the levers will be delivered to the recoil --clevice in such a way that the cutter blade will" be started on its return stroke.

' I h modified forme t invention the I frame is indicated bythe reference character 5, and as shown the frame is formed with erti al gr ov s disp ed nt rmed t the ends thereof, the grooves having inclined walls to accommodate the partition 6, which is fo m d wi h sla ing ac s to insure a w dg fi b t ene partitio an ame of the device. 1 p In this form of the invention ayi'eldable member ndicate y: he refere e character 7 is positioned at each side, of the par tition, each yieldable rruember embodying nested expansion springs, the ends thereof being fitted in the, caps ,T seeapw with the-caps 25, an suppor bear ngs that engage the levers 10' ,the levers 10 be-,

ing also engaged the bearings 11' that are h ld in BSSQ in the ends of the frame of he evi The levers 10 are substantially long and extend downwardly topoints where-they'will b e g ged by the cutterh a of the cutt bar, to estrict mome t jlm of the cutter head.v

In orde that the members. 7 will be held: against displacement, a'pin 12 is :provided, which-pin is secured in the partition, 6, the

ends of the :pin extending into the inner caps 8 of the springs 7 Due to this construction, it will be obvious that the required 'resiliency'of the bufier is. provided, butdue o ect that two yieldable elements are provided, the pulsations of the springs will be greatly reduced, :thereby reducing wear to a minimum. y

Having thus described the invention what. is claimed is: q

1. A bufierfor reciprocating: cutter hers, having heads comprising "a frame :to, be mounted above. the cutter bar *head of- :3, outter @bar, expansion springs mounted within the frame, and normally held under predetermined tension levers disposed between the ends of the springs and the frame, the lower ends of the levers extending below theframe and adapted to be disposed in the path of travel of the cutter bar head, and said levers adapted to take up momentum of the cutter frame and lying in the path of travel of the,

cutter bar head to take up momentum ofthe cutter bar head and cutter bar connected therewith. p

3. The combination with the reciprocating cutter bar of an agricultural machine, and the cutter bar head thereof, of a buffer comprising compressible means including levers normally urged outwardly by the compressible means and said levers lying within the path of travel of the cutter bar head and moved laterally by the cutter bar head to take up momentum of the cutter bar head.

4. The combination with the cutter bar head of an agricultural machine, of a buffer including a frame, a plurality of nested colled springs mounted within the frame, rockable levers mounted between the ends ofthe springs and the frame, said springs normally urging the upper ends of the levers outwardly said levers extending downwardly below the frame and lying within the path of travel of the cutter bar head, to take up the momentum of the cutter bar head, and cutter bar connected therewith, and means for adjusting the throw of the levers.

5. The combination with the cutter bar head and cutter bar of an agricultural machine, of a buffer comprising a frame, expansion springs mounted within the frame and normally held under predetermined tenslon, levers mounted within the frame, bearings at the ends of the springs and engaging the levers, bearings on the frame and engaging the levers, the last mentioned bearings lylng in a plane below the first mentioned hearings to force the lower ends of the levers inwardly, and said levers lying within the path of travel of the cutter bar head, to take up momentum of the cutter bar head.

6. The combination with the cutter bar head and cutter bar of an agricultural machine, of a buffer comprising a frame, expansion springs mounted within the frame and normally held compressed under a predetermined tension, bearings removably mounted at the ends of the springs, bearings mounted on the frame, said bearings having rounded outer surfaces and substantially flat inner surfaces, levers having flat surfaces mounted between the bearings at each, end' of the frame, the rounded surfaces of the bear-:1 mgsengagmg the flat surfaces of thelevers,

and said'levers arranged to co-actwith'the cutter bar head, to store. themomentum of the cutterbar.

7 .-A buffer for-reciprocating cutter bars having heads comprising a frame, expansion springs mounted withintheframe and normally held under tension, levers mounted between the ends of the springs and frame, bearings disposed between the springs and levers, bearings disposed between the levers and frame, said bearings having rounded surfaces engaged by the levers, said levers adapted to rock on thebearings, and said levers extending into the path of travel of the cutter bar head to take up movement thereof, and means for securing this device to the machine.

8. A buffer for reciprocating cutter bars having heads, comprising a frame, nested expansion springs mounted within the frame, levers mounted within the frame and held within the frame by the outward pressure of the springs, the lower ends of the-levers lying within the path of travel of the cutter bar head of the cutter bar with which'the buffer is used to absorb momentum of the bar, bearings supported by the frame and ends of the springs and over which the levers move. 7

9. The combination with the cutter bar head of an agricultural machine, of a buffer mounted in close relation to the cutter bar head, said bufl'er comprising nested expansion springs, levers pivotally mounted intermediate their ends and held in position by the outward pressure of the springs, said springs acting against the upper ends of the levers to nomally urge the lower end of the levers inwardly, and the lower ends of the levers lying in the path of travel of the cutter bar geag to regulate movement of the cutter bar 10. The combination with the cutter bar head of an agricultural-machine, of a bufier mounted hear the cutter bar, said bufi'er comprising a frame, coiled springs supported within the frame, caps at the ends of the springs, said caps having recesses, bearings in the recesses, said bearings having lugs at their ends,. levers disposed between the ends ofthe springs and the frame, bearings carried by the frame, said bearings having lugs at their ends, said levers having recesses to receive the lugs to prevent lateral movement of the bearing members, and said levers extending in the path of travel of the cutter bar head'with which the device is used to restrict momentum thereof.

11. In a buffer for reciprocating cutter bars,"a support, expansion springs mounted on the support, caps fitted over the ends of the springs, bearings mounted on the caps and urged laterally the Springgsaid bearings having rounded'surfaces, levers having flatssurfac'es- 'restin'gon the rounded surfaces 7 of the'bearings to rockably' support the levers,

Y and, toothed means" for preventinglateral movement of the levers and bearings. In testimony that I Claim the foregoing as my own, I have hereto aflixed my signature.

NATHANIEL B. STONE. 

